Research suggests that ASD may have a genetic basis; however, the genetics of autism appears to be complex and it is unclear whether ASD is explained by multigene interactions or by rare mutations with major effects. Past and current scientific studies tend to support the premise that there is a strong genetic element in the development of ASD and autistic traits.
To date, a recent genetic study of ASD has identified 65 genes that contribute to autism. This includes 28 genes in which there is high confidence that they play a role in the risk of developing ASD. The 2015 study involved a multicenter US research team led by Stephan Sanders, PhD of the University of California. It confirmed that there are six larger regions of the genome that are prone to copy number variants that may contribute to autism risk. The study demonstrated that ASD-associated genes fall into two main functional categories. The first is related to the development and function of synapses and the second involves chromatin, so that there may be two separate biological paths to the disorder, making the genetics somewhat complex.
In addition, the study may also provide some clues to the well-documented sex disparity in ASD. It is known that ASD is diagnosed three to four times more commonly in boys than girls. One possible reason for this disparity is that females tend to be protected against autism risk. The study concluded that for girls to develop ASD, they may need a broader mutation burden than boys.
Source: Sanders SJ, He X, Willsey AJ, Ercan-Sencicek AG, Samocha KE,
et al. Insights into Autism Spectrum Disorder Genomic Architecture and Biology from 71 Risk Loci.
Neuron. Vol 87(6):1215-1233. September 23, 2015. Available at:
http://www.cell.com/neuron/abstract/S0896-6273(15)00773-4. Accessed February 7, 2018.
